This killdeer is sitting on 4 eggs in a break in the pavement and has been for about a month. They're about to hatch.
Killdeer are an interesting kind of Plover... they always nest on the ground. If a predator gets too close to their nest, the mamma killdeer calls out in distress and begins flapping around on the ground as if her wing is broken. The predator, sensing easy prey, chases after her. She continues this routine as she makes her way away from the nest, luring the predator to follow. When she and the predator are far from the nest, she suddenly heals and flies away. I don't know why this works (dim-witted predators?) but it must, because there are a lot of killdeer in the world.